Poor Idle

14467 Views 23 Replies 10 Participants Last post by The Pope, Dec 13, 2008

turbo2go

Discussion Starter · Jul 25, 2007 (Edited by Moderator)

Please help I thought I understand these cars but I guess not. I just put in head gasket,timing is correct,vac lines seam ok,new plugs,pvc valve new,tried changing throttle body with differrent ais and tps sensor but it will not idle very well stalls when coming to a stop.car has i year old mp logic module. it will idle ok after about 10 mis of driving.:bang head

1 - 20 of 24 Posts

NAJ

· #2 · Jul 25, 2007

A few Questions ;
Was this problem present before you did the Engine work?
Did you Disconnect the Coolant Temp Sensor with the Engine Running when you set the Ignition Timing?
When the Engine is Cold and the Stalling Condition is Present will the Engine stay running if you keep your foot on the Throttle?
After it reach's Operating Temp and the problem is gone what is the Idle Speed of the vehicle and does the Speed Increase or Decrease when the Cooling Fan comes on or the AC Compresor Engages.
Are there any Fault Codes Set?

turbo2go

Discussion Starter · #3 · Jul 25, 2007

Thanks NAJ for the reply great questions,here is some answers 1) yes it had the same problem before head gasket was done.2)coolant sensor was disconnected to time it.3) yes it will stay running if I press the gas.4)when the fan kicks on the idile drops a a bit,I think and no a/c. And no codes by key flick only 33 and 12.

NAJ

· #4 · Jul 26, 2007

Sounds like you are having an AIS Control issue especially when you say the "Idle Drops" when the Fan Cycles on.This will not set a Fault Code unless the Controller cannot bring Idle Speed High or Low into Specs.
Since the Controller actually has No Idea where the AIS is (in terms of steps in or out) it assumes it is in a certain spot so lets start with Basics and Check Base Idle and Reset AIS.
First,is the Throttle Plate,AIS Pintle and Housing Clean of Carbon Buildup?
No,Clean, then Proceed
Yes,Proceed
Start Vehicle and let it Run until it reach's Operating Temp and will Idle by itself.
With the Vehicle Running create a Large Vacuum Leak either by Removing the Brake Booster Line or the PCV Valve from the Hose.Remove Slowly so the Engine does not Stall.Idle Speed will increase drastically.At this point the Controller will be Attempting to Correct the High Idle Speed by Commanding the AIS Motor to "Step In" to close off the Passage.
Wait 1 Minute and Unplug the AIS Wire Connector.
NEVER UNPLUG A MOTOR WHILE THE CONTROLLER IS MOVING IT!!!!!
This Will Cause an Electrical Spike Which Will Damage The Drivers in The Controller(That is why we waited 1 Minute)
With the Engine still running and the AIS Disconnected Slowly Reattach the Vacuum Line Previously Disconnected.(The Vehicle May Stall,That is OK)
Now we are at Base Idle(Minumum Throttle Plate Opening) Without AIS Control.
Set Base Idle to 550-575 RPM.
You may have to remove the Tamper Proof Cover over the Base Idle Screw.
Once Base Idle is Set Shut the Engine Off and Reconnect the AIS Connector.
When you Cycle the Key to Start the Controller will Automatically Reset the AIS to a Restart Position.
Restart Vehicle and Check Idle Operation.
In your case you may have to wait until the Engine is Cold to be sure but let it run until the Cooling Fan Cycles On and see if RPM Increases,if it does you should be good.
If the Problem still Persists we will have to get into AIS Diagnostics to determine if you have a Faulty AIS,Wiring Problem or Faulty Controller.

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turbo2go

Discussion Starter · #5 · Jul 27, 2007

Thanks very much I will let you know how it goes.

turbo2go

Discussion Starter · #6 · Jul 31, 2007

Thanks for the great tech tip. it helped diag the throttle body problems I had. It is running a little better,but it is running rich,fumes so bad eyes water.changed hall effect,rotor, wires,plugs,map,sensor,fuel regulater,rail,injectors(one was badly fouled) and power module.Thanks to all.:bang head :bang head

akronboy89

· #7 · Sep 9, 2007

so i guess this has been done all ready and it did not work.
and the speedometer is probably lose or came off.
i heard it could b the speed sensor
and the guy im getting it off of said he thinks it might have a vacuum leak
i have no clue...

moparfwdsleeper

· #8 · Sep 9, 2007

akronboy89 said:
so i guess this has been done all ready and it did not work.
and the speedometer is probably lose or came off.
i heard it could b the speed sensor
and the guy im getting it off of said he thinks it might have a vacuum leak
i have no clue...

Maybe it's cause it's late/early I guess. But i'm confused with your post.

Speedometer? It only tell's you the speed your moving... I can't really see how it is lose or came off and don't able to tell as it is in front of the driver in the cluster. If you are talking about the cable, it only operate's the speedometer needle. Those two I can't see playing any role in this kind of issue. But who know's?

NAJ!

Speed sensor could tie into this. From my understanding, it sending voltage signals to the computer for every rotation the transaxle.

It's early and i'm very sleepy

Wouldn't that tie into the TPS and AIS somehow? Something in my memory is thinking that the speed sensor is tied into those two somehow

akronboy89

· #9 · Sep 9, 2007

haha my bad i ment speed odometer lol i been up to long
it dont tell you how fast your going

moparfwdsleeper

· #10 · Sep 9, 2007

Yeah I hear you there. After this post i'm crawling to bed before I pass out in this chair.

If your's isn't working. Just the exterior of the cable. Your looking for breaks on the platic mostly found at the ends on the cable.

Do you have cruise control on the vehicle?

NAJ

· #11 · Sep 9, 2007

I am confused, what are we talking about? Maybe you should start a new thread and explain your driveability concern.

akronboy89

· #12 · Sep 9, 2007

NAJ said:
Sounds like you are having an AIS Control issue especially when you say the "Idle Drops" when the Fan Cycles on.This will not set a Fault Code unless the Controller cannot bring Idle Speed High or Low into Specs.
Since the Controller actually has No Idea where the AIS is (in terms of steps in or out) it assumes it is in a certain spot so lets start with Basics and Check Base Idle and Reset AIS.
First,is the Throttle Plate,AIS Pintle and Housing Clean of Carbon Buildup?
No,Clean, then Proceed
Yes,Proceed
Start Vehicle and let it Run until it reach's Operating Temp and will Idle by itself.
With the Vehicle Running create a Large Vacuum Leak either by Removing the Brake Booster Line or the PCV Valve from the Hose.Remove Slowly so the Engine does not Stall.Idle Speed will increase drastically.At this point the Controller will be Attempting to Correct the High Idle Speed by Commanding the AIS Motor to "Step In" to close off the Passage.
Wait 1 Minute and Unplug the AIS Wire Connector.
NEVER UNPLUG A MOTOR WHILE THE CONTROLLER IS MOVING IT!!!!!
This Will Cause an Electrical Spike Which Will Damage The Drivers in The Controller(That is why we waited 1 Minute)
With the Engine still running and the AIS Disconnected Slowly Reattach the Vacuum Line Previously Disconnected.(The Vehicle May Stall,That is OK)
Now we are at Base Idle(Minumum Throttle Plate Opening) Without AIS Control.
Set Base Idle to 550-575 RPM.
You may have to remove the Tamper Proof Cover over the Base Idle Screw.
Once Base Idle is Set Shut the Engine Off and Reconnect the AIS Connector.
When you Cycle the Key to Start the Controller will Automatically Reset the AIS to a Restart Position.
Restart Vehicle and Check Idle Operation.
In your case you may have to wait until the Engine is Cold to be sure but let it run until the Cooling Fan Cycles On and see if RPM Increases,if it does you should be good.
If the Problem still Persists we will have to get into AIS Diagnostics to determine if you have a Faulty AIS,Wiring Problem or Faulty Controller.

this has been done already and it did not work :bang head :bang head

NAJ

· #13 · Sep 9, 2007

PM me with your problem and I will see what I can do to help. do not leave out any details, all info helps. Do not forget Year,Model, Engine.

penstar4ever

· #14 · Apr 11, 2008

Re: help with poor idle

Take out your A.I.S. motor and measure it from the base,it should be less that 1 inch,to retract it you can screw it in or take it to the dealer that has a special tool that hooks up to the battery and ais motor and can let you know if its stuck and actually watch it move in/out,if you know some one at a mopar shop,he can do it.Good luck.........

87glhs

· #15 · Nov 27, 2008

Re: help with poor idle

Check to see if the four-bladed metal disc (encoder) in your distributor is in any way loose. This is a common problem with that era of 2.2's--the disc is what triggers the HEP module (the black "puck" in your distributor). MOPAR used a nylon adaptor plate to mount the disc to the distributor shaft. In time, the disc becomes loose on the plate and starts to float around. I've seen it happen both when the engine is cold and/or hot.

When you start having the idle/missing problem, pull the cap, rotor, and HEP module out of the distributor. Then try to wiggle the metal encoder disc around. It should not move AT ALL. If you see any significant looseness, you'll have to replace the distributor. AA sells one (mine came with a new HEP) for about $50.

Good luck.

specialK

· #16 · Nov 27, 2008

Re: help with poor idle

I had the same issue after putting in my engine, turned out to be a bad vacuum leak at the power booster.

douglas87

· #17 · Dec 1, 2008

Re: help with poor idle

So do all these older td's have ais problems?

douglas87

· #18 · Dec 1, 2008

Re: help with poor idle

What is the adjustment screw by the ais motor on the throttle body for anyway?

NAJ

· #19 · Dec 1, 2008

4

Re: help with poor idle

AIS failure is not uncommon and not anymore prevalent than it is on todays vehicles.
The majority of idle problems on TD's is related to vacuum leaks and carboned throttle plates.
The difference is that when looking at vehicles that are 20+ years old with OE parts the failure rate seems higher.
The screw is used to hold the throttle at its minimum opening(base idle) and all AIS movement by the controller is based on this being correct.

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douglas87

· #20 · Dec 2, 2008

Re: help with poor idle

Thanks for the help

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